How do you assemble a boat motor?

Motor Toy Boat Problem (veering left)..?

• For my engineering class competition we have to create a boat to transport an orange around a small pond-like fountain area. We built our boat out of expanded polystyrene (styrofoam) and carved it into a normal v-shape boat design via sandpaper. We attached a motor to the back connected to a battery back holding 8 D batteries that is glued on the top of the boat. Overall a really great design, but the boat seems to veer left right when we turn the motor on. We tried installing a rudder and testing it when the rudder was adjusted at different angles, but it would either have no affect (when angle was really small) or it would overcompensate for the left turning. We also tried re-glueing the motor to the back of the boat and adjusting that, but the boat is still not going straight. We just need it to basically go straight or even slightly to the left. We are in complete left circles right now. PLEASE HELP!!!! Thank you so much!

• Answer:

  Probably the easiest approach is to modify the rudder. If you have a rudder that makes it turn too far to the right, decrease the amount of rudder in the water (trim it to make it smaller). That will make it less effective. Somewhere between the whole rudder and no rudder will be straight travel. You can tune the steering that way. Another possibility is to skew the motor/propeller alignment so that the propeller points a little toward right (the starboard side). (This presumes the propeller is on the back, pushing the boat.) Another possibility is not to skew the motor/propeller, but move them more to the left of centerline. By pushing the back left side of the boat, the boat will tend to turn toward the right. However, this approach will change the balance of the boat, so you may need to move other weight to the right of the centerline.